Updated Seating Protocol for Zirconia-Based Restorations

Recent research has shown that saliva contamination can hinder the bonding of solid zirconia and zirconia oxide copings. When a zirconia crown or bridge is tried in the patient’s mouth and comes in contact with saliva, the phosphate groups in the saliva bind to the zirconia oxide and cannot be rinsed out with water. Attempting to use phosphoric acid (which is full of phosphate groups) to “clean out” the saliva only makes the problem worse.

BruxZir™ Solid Zirconia, BioZX2 Translucent Zirconia, and all PFZ (porcelain fused to zirconia) restorations are fabricated from solid zirconia oxide material, which exhibits a strong affinity for phosphate groups. We can take advantage of this fact with phosphate-containing primers such as Monobond Plus (Ivoclar Vivadent) and Z-Prime™ Plus (Bisco), or with cements such as Ceramir® Crown & Bridge (Doxa Dental) to increase our bond strengths to zirconia oxide. Unfortunately, saliva also contains phosphates in the form of phospholipids. To successfully remove saliva, it is now suggested that after try-in and before priming, the crown should be cleaned with Ivoclean, a zirconia oxide solution from Ivoclar Vivadent. This zirconia oxide solution is placed inside the restoration for 20 seconds and then rinsed out. Due to the large concentration of free zirconia oxide in the Ivoclean, it acts as a sponge and binds to the phosphate groups that were previously bonded to the restoration.

The suggested protocol is:

1. Try in zirconia-based restoration 2. Rinse saliva out of restoration with water 3. Place Ivoclean in restoration for 20 seconds, rinse and dry 4. Apply primer and then cement with product of your choice Once the Ivoclean is rinsed out, you will have a fresh bonding surface for the Monobond Plus, Z-Prime Plus or Ceramir to bond to.